Search PubMed⌕ Search

Biomedical subjects

C Berman

Publications and source records attributed to C Berman.

At least 73 records · Page 4Linked to original sources
PubMed1986

Prostatic effects induced in dogs by chronic or acute oral administration of 5 alpha-reductase inhibitors.

A series of 4-azasteroidal 5 alpha-reductase inhibitors was tested in dogs to determine the effect of chronic (35-44 day) oral administration on prostate size and histology and acute oral administration on prostatic concentrations of testosterone (T) and dihydrotestosterone (DHT). The extent to which the results of the two tests were correlated was also studied in order to see whether the acute test could be used to predict activity in the chronic test. Six delta 1 analogs of the potent 5 alpha-reductase inhibitor, 4-MA (17 beta-N,N-diethylcarbamoyl-4-aza-4-methyl-5 alpha-androstan-3-one) were uniformly active at low dosage levels (less than or equal to 3 mg/kg) in both types of assay whereas several C1-C2 saturated analogs exhibited little activity in the chronic test. The nature of the side chain and whether there was a methyl or a proton at 4-N did not dramatically influence the activity of delta 1 compounds. There was a broad general agreement between the results of the two kinds of test in that if a compound acutely decreased the prostatic concentration of DHT it was likely to reduce prostate size and alter prostatic histology when given on a chronic basis.

5-alpha Reductase Inhibitors↗
PubMed1986

5 Alpha-reductase inhibitory and anti-androgenic activities of some 4-azasteroids in the rat.

Inhibition of 5 alpha-reductase and anti-androgenicity were studied in rats treated with various 4-azasteroids. The known inhibitor, N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxamide (4-MA) served as a reference compound, and analogs of this basic molecule were assayed. Enhancement of enzyme inhibitory potency was usually seen with delta 1 analogs, whereas reduction in activity was noted with substitutuents such as delta 5, a spirotetrahydrofuran ring at C-17 or 4-deaza groups. Many of the 4-azasteroids had a much greater oral anti-androgenic effect against testosterone propionate (TP) than dihydrotestosterone propionate (DHTP). This difference in activity versus the two androgens is believed to reflect the necessity for TP to undergo reduction to DHT before becoming capable of stimulating prostatic growth. Inhibition of 5 alpha-reductase by active compounds prevented the conversion, thereby producing an anti-androgenic effect. In this regard, certain delta 1 analogs of 4-MA, particularly those bearing a 17 beta-(N-tert butylcarbamoyl) group, proved very effective against TP but were relatively inactive versus DHTP.

Androgen Antagonists↗
PubMed1986

Azasteroids: structure-activity relationships for inhibition of 5 alpha-reductase and of androgen receptor binding.

A series of steroids, primarily 4-azasteroids, were prepared and tested in vitro as inhibitors of human and rat prostatic 5 alpha-reductase and of binding of dihydrotestosterone to the rat androgen receptor. The primary structural modifications were changes of the A ring and of moieties attached at the C-17 position of the steroid nucleus. New A-ring modifications included the 4-cyano-3-oxo-delta 4 system in the carbocyclic series and 1 alpha-CN, 1 alpha-CH3, 1 alpha,2 alpha-CH2, 2 beta-F, 2-aza, 2-oxa, and A-homo changes in the 3-oxo-4-aza series. In addition, 4-azasteroids with a D-homo ring or methyl substitution at C-7 (alpha and beta) or C-16 (alpha and beta) were prepared. The majority of the C-17 substituents were prepared from reactive intermediates derived from the 17 beta-COOH. Enhanced 5 alpha-reductase inhibition in both the human and rat enzyme assays is seen with 4-CN substitution on 3-oxo-delta 4 steroids and with a C-17 side chain incorporating a lipophilically substituted semipolar group on the 4-aza-3-oxo-5 alpha-androstane nucleus. Fewer highly active compounds were found in the human enzyme assay than in the rat assay. Structural requirements for inhibition of the rat androgen receptor are much different from those for inhibition of the enzyme. The 17 beta-OH moiety enhances potency more than any other feature while introduction of double bonds at C-1 or C-5 in the azasteroid gives a small improvement. Azasteroids unsubstituted at the 4-position show greatly diminished receptor activity.

5-alpha Reductase Inhibitors↗
PubMed1986

Chlorhexidine. An adjunct to periodontal therapy.

Chlorhexidine is an effective antimicrobial agent. Its application can enhance periodontal therapy. The pharmacology of chlorhexidine and suggestions for its use are outlined. In addition, its potential for inducing cancer and bacterial resistance are discussed.

Absorption↗
PubMed1984

Azasteroids as inhibitors of rat prostatic 5 alpha-reductase.

A series of A-ring heterocyclic steroids has been prepared and tested for inhibition of rat prostatic steroid 5 alpha-reductase in vitro. Strikingly high inhibitory activity was found with a group of 17 beta-substituted 4-methyl-4-aza-5 alpha-androstan-3-ones. These compounds were prepared from 3-keto-delta 4-precursors by oxidative (O3 or NaIO4-KMnO4) A-ring cleavage followed, in turn, by ring closure with an amine and hydrogenation over platinum catalyst. Other A-ring azasteroids were made by Beckmann rearrangement of oximes of 2-oxo-A-nor, 3-oxo- and 4-oxo-5 alpha-androstanes. An A-nor-2-oxo-3-azasteroid was prepared by oxidative decarbonylation of a precursor 2,3-dioxo-4-azasteroid with m-chloroperbenzoic acid. A-ring modifications of the 4-azasteroids included delta 1-unsaturation, 2- and 4-substituents, and 3-carbonyl replacements. Side chains at the 17-position were varied with an emphasis on carboxylate derivatives (salts, esters, and amides).

5-alpha Reductase Inhibitors↗
PubMed1984

Sexuality as a treatment issue with a special population of adolescents.

The handicapped adolescent population heretofore has not been properly identified or serviced. These adolescents have to deal with body image and sexual identity problems. Working with the adolescent individually, in groups, and in a therapeutic community setting, we have developed methods of dealing with the issue of sexuality.

Adolescent↗
PubMed1983

Human beta-nerve growth factor gene sequence highly homologous to that of mouse.

Nerve growth factor (NGF) is thought to have a profound effect on the development and maintenance of sympathetic and embryonic sensory neurones (see refs 1-3 for review). NGF activity isolated from the male mouse submaxillary gland (MSG) consists of three types of subunits, alpha, beta and gamma, which specifically interact to form a 7S, approximately 130,000-molecular weight (Mr) complex. The 7S complex contains two identical 118-amino acid beta-chains, which are solely responsible for the nerve growth-stimulating activity of NGF. While NGF is found in almost all vertebrates, most research has focused on murine NGF, as the mouse male submaxillary gland contains higher levels of this polypeptide than other tissues. Even so, beta-NGF comprises only approximately 0.1% of the protein in this small gland, which has made the study of this polypeptide difficult. The amino acid sequence of the mouse NGF beta-chain has been determined and some information has been obtained regarding the size of a mouse precursor molecule, pro-beta-NGF, but little was known about the structure and relatedness of beta-NGF from other vertebrates. Here we describe the isolation of mouse beta-NGF complementary DNA (cDNA) and present its nucleotide sequence, which predicts a prepro-beta-NGF molecule of Mr 27,000 (27K) and a pro-beta-NGF molecule of Mr 25K. We have used the mouse beta-NGF cDNA clone to isolate the human beta-NGF gene, the coding regions of which are highly homologous to the mouse prepro-beta-NGF nucleotide and amino acid sequences.

Animals↗
PubMed1983

Dagga (cannabis) usage among medical students in Johannesburg.

Of 1 020 undergraduate medical students at the University of the Witwatersrand surveyed in 1981 as regards attitudes to and patterns of illicit drug use 868 completed the questionnaire; 32,4% had tried dagga (cannabis) and 16,4% were still using the drug. There was a large increase in the number of students using the drug as they advanced through their studies (6% of the 1st-year class as against 24% of the 5th-year class). The timing of dagga use and previous experimentation with habit-forming drugs are mentioned, and reasons for non-experimentation and attitudes towards legalization of dagga are analysed.

Attitude↗
PubMed1981

The dying patient -- attitudes and responses.

This study was designed to ascertain the attitudes and responses of the dying patient, both to himself and to those around him, particularly the medical care team. The sample chosen consisted of 75 patients suffering from various terminal illnesses. We studied the patients' reactions on being told about their illness, the manner in which they were told, how they reacted to their illness and the way the medical care team, family and friends treated them. The role of religion as a support system with regard to 'accepting death' was investigated. Recommendations regarding doctor-patient relationships are made.

Adolescent↗